use travis_wait to avoid no output error

Author: wing328

.travis.yml

@@ -100,7 +100,7 @@ script:
   # fail if generators contain tab '\t'
   - /bin/bash ./bin/utils/detect_tab_in_java_class.sh
   # run integration tests defined in maven pom.xml
-  - mvn -q --batch-mode verify -Psamples
+  - travis_wait mvn -q --batch-mode verify -Psamples
 ### docker-related tasks have been moved to CircleCI
   # docker: build generator image and push to Docker Hub
   #- if [ $DOCKER_HUB_USERNAME ]; then docker login --email=$DOCKER_HUB_EMAIL --username=$DOCKER_HUB_USERNAME --password=$DOCKER_HUB_PASSWORD && docker build -t $DOCKER_GENERATOR_IMAGE_NAME ./modules/swagger-generator && if [ ! -z "$TRAVIS_TAG" ]; then docker tag $DOCKER_GENERATOR_IMAGE_NAME:latest $DOCKER_GENERATOR_IMAGE_NAME:$TRAVIS_TAG; fi && if [ ! -z "$TRAVIS_TAG" ] || [ "$TRAVIS_BRANCH" = "master" ]; then docker push $DOCKER_GENERATOR_IMAGE_NAME; fi; fi